The only thing that is more expensive as far as I have ever experienced going back to 2004 which was the first of my 15 trips was eating all western food. Sure there is a Tony Roma's in Bangkok. A hard rock cafe in Pattaya and things like that. But lots of Thai rice and noodle and soup dishes and some occasional German food or a Full English Breakfast now and then along with a Sunday Carvery now and then as well as the specials that Robins Nest used to have such as the Lasagna, suited me just fine, A nice sized 40 or even 50 sq meter condo rents for about 1/2 of a similar thing here in many parts of the USA. My health insurance is now on Medicare so I am paying that regardless of me spending long term in Thailand so that doesn't count in my cost equation. Costs for touristy things like visiting parks, gardens, zoos, etc. are comparable or cheaper in Thailand than in the USA. Certainly are cheaper when you look at what they now charge to go to big corporate places such as Disney world, Universal world, tec. The Dallas Texas zoo was very reasonably priced as is the fantastic San Diego Zoo. Nong Nooch Garden just outside of Pattya is reasonable. I miss the old Dusit zoo in bangkok. That was like an oasis.
Yes foreign wine or other hard liquor can add up but I rarely drink that. So if I were to pull up stakes and totally move to Thailand, it would cost me about 25% less of what very similar living and eating here in the USA, and would go down from there if I was really penny pinching. Basically I plan for $3,000 a month, budget for $4,000 a month, can afford $5,000 a month.